The present embodiments relate to valves and, more particularly, to swing check valves.
A check valve is a type of valve that generally allows fluid to flow through the check valve in only one direction. A swing check valve utilizes at least one flapper or disc which rotates (i.e., pivots) about an axis between open and closed positions. When in the closed position, the flapper sits on a housing of the check valve and blocks a flow of fluid through the check valve. When the flow of fluid into the check valve reaches a sufficient pressure (i.e. the cracking pressure), the flapper opens by rotating about the axis. Swing check valves are generally designed for a specific cracking pressure depending on the application. When the fluid pressure drops below the cracking pressure and/or back pressure occurs, the flapper then rotates back to the closed position, preventing fluid from flowing back into the swing check valve.